The proposed study represents the beginning of a long-term project to investigate the role of the spinal cord and peripheral innervation of pelvic organs in sexual function. A particular goal of this project is to compare the anatomical and physiological organization of sexual function in males and females. This aspect of the study is motivated by reports that sexual behavior and physiology of males and females show both similarities and differences. The human relevance of this research concerns the understanding of normal sexual function and of the devastating deficits in sexual dysfunction suffered after lesions of the spinal cord, peripheral nerves or as a consequence of systemic diseases such as diabetes. The specific aims of the study are to examine in rats of both sexes the anatomy and physiology of the spinal cord as it relates to sexual function. The anatomical studies are motivated by the fact that the peripheral course of pelvic nerves and the spinal organization of somatic and autonomic afferents and efferents are not well understood. These results will form a crucial basis for the understanding of the coordination of the somatic, sympathetic and parasympathetic systems in sexual physiology. These studies will include tract-tracing experiments using fluorescent dyes, horseradish peroxidase and lectins to analyze somatic and autonomic afferents and efferents innervating sexual organs. Other anatomical studies are motivated by the necessity to analyze the anatomy of transmitter-specific pathways in the spinal cord. Transmitters to be analyzed include monamines, and neuropeptides which may all play an important role in the spinal control of sexual reflexes. These studies will use immunohistochemical and histochemical techniques to localize these putative neurotransmitters in the spinal cord. The physiological studies will examine in anesthetized, spinalized rats of both sexes the spinal reflexes elicited by electrical stimulation of afferents (both somatic and autonomic) innervating sexual organs. Reflexes will be recorded from efferents (both somatic and autonomic) contained in peripheral nerves. These studies are motivated by the fact that these reflexes, under the control and coordination of supra-spinal centers, probably represent an integral part of normal sexual functioning.